The invention relates to a joining and connecting element for corrugated pipes with at least one hollow core space encompassed by a housing for receiving a pipe end, a connecting portion at the end of the housing facing away from the hollow core space, an abutment shoulder, formed on the housing in the region of the connecting portion, with a sealing face, and a sealing configuration.
Joining and connecting elements or connecting fittings of this type are known in various implementations. Swiss Patent CH 645 448 describes, for example, a connecting fitting for a flexible corrugated tube. This connecting fitting comprises a housing with a hollow core space, wherein one end of the corrugated tube or corrugated pipe is slid into this hollow core space. Furthermore, on the housing a recess is provided into which is slid a locking device and by means of which the end of the corrugated tube is retained in the hollow core space. On the end of the housing facing away from the hollow core space is disposed a connecting portion in the form of a threaded stub and on the rear end of this threaded stub the housing comprises an abutment shoulder with a sealing face. This threaded stub serves for connecting the fitting with this housing by threading it into a threaded bore in the wall of a housing or the threaded stub is passed through a bore and subsequently tightened with a nut on the inside. To generate a tight connection between the abutment shoulder on the connecting fitting and the wall of the housing, it is necessary to emplace a seal in a manner known per se. In order to be able to withstand the relatively high screw-in forces, these seals must comprise a material resistant to compression, for example, they must be made of paper-base laminates. Such seals can only even out irregularities in the contact region to a limited extent. They additionally have only a low elasticity or sealing tolerance, such that the sealing effect is lost even if the threaded connection is only slightly released. There also exists the danger that during the assembly of the connecting fitting the seal is not emplaced resulting in serious damages. In a tight implementation of the connection between a corrugated pipe end and the fitting, a seal is also emplaced in the hollow core space disposed between the outer shell of the corrugated pipe and the shell of the hollow core space. This seal is placed either prior to assembly into the hollow core space of the fitting, or it is slid over the end of the corrugated pipe, and the corrugated pipe and the fitting are subsequently plugged together. Again, the danger exists here that this seal is lost, or that, due to improper sliding of the pipe end into the fitting, the seal is deformed and that its effect is thereby impaired.
It is the task of the invention to provide a joining and connecting element for corrugated pipes in which for tight connections no seals need to be emplaced and in which soft sealing materials can be used as seals, and during assembly, additional emplacements of seals are avoided and the working process is thereby simplified.
This task is solved by the characteristics defined in the characterizing clause of the independent claim. Advantageous further developments of the invention are evident on the basis of the characteristics of the dependent claims.
The tight connection between the seal and the sealing face on the abutment shoulder of the housing provides the advantage that the seal is always positioned at the correct location of the housing and that it cannot be lost. The seal is a structural member of the housing and, thus, of the joining and connecting element, such that when using the joining and connecting element or its threaded connection with, for example, the wall of a housing, a tight connection is always obtained between the joining element and the part with which the corrugated pipe is to be connected. The connecting portion on the housing of the joining element can be a threaded stub with outer threading, or a stub with inner threading, or a flange with fastening screws. In the case of inner threading as well as in the case of outer threading, the abutment shoulder is positioned on the inner end of the threading and is directed radially outwardly or inwardly. In the case of a flange, this flange itself forms the abutment face or sealing face. Staying elements formed on the sealing face and abutment face on the housing lead to the further advantage that the pressing forces applied through the screwing do not need to be absorbed by the seal but are transferred via these staying elements to the abutment shoulder and thus to the housing of the connecting element. This yields a significantly increased range from which the materials for the seal can be selected, such that also soft materials such as, for example, polyester elastomers can be used. Due to the high elasticity of such seals, deviations of form such as, for example, unevenness in the area of the sealing faces and also variations of the pressing forces due to vibrations can be evened out. This leads to substantially greater tightness and higher security of the sealing configuration. In order to be able to utilize the elasticity of the seal in the longitudinal direction of the joining and connecting element, it is proposed to structure the height of the staying elements in the direction of the longitudinal axis of the housing to be less than the thickness of the seal. Simultaneously, the staying elements are in radial direction of a width which is less than the width of the seal, such that a closed sealing ring is provided.
The seal in the hollow core space of the joining and connecting element is also fixedly connected with the housing, such that here also the advantage is obtained that the inner seal is a structural member of the housing and that it cannot be lost. Due to this tight connection along the inner shell of the hollow core space the shape of the seal is also retained, and the seal is not deformed when sliding the pipe end into or out of the hollow core space nor is it moved from its sealing location. In this case also soft sealing materials are preferably used which are suitable for a tight connection with the materials of the housing. This is, for example, also a polyester elastomer.
The tight connection between the seal(s) with the housing is formed by surface bonding [connection] on the contact faces. To this end the housing is produced first, for example by injection molding [casting] of a synthetic material or metal, or of a combination of synthetic material and metal. Herein the same materials are used which are also used, for example, in the known connecting fittings, for example, as the synthetic material a polyamide and as the metal, for example, stainless steel. The seals are formed by way of injection molding onto the prefabricated housing part such that a two-component molded [cast] part is produced and on the contact surfaces between the seals and the housing, a fixed surface connection is provided.
Disposing two pairs of staying elements on the abutment shoulder of the housing is advantageous since, due to the symmetrical distribution at a spacing of 90xc2x0 each, uniform contact distributed over the circumference results. Two staying elements each are disposed diametrically opposing one another with one pair being disposed on the inner diameter of the abutment shoulder and the second pair on the outer diameter of the abutment shoulder. Therewith good contact is ensured even with deviations developed during shaping.
A joining and connecting element structured according to the invention facilitates handling and assembly, since no auxiliary parts are required in order to establish a tight connection, for example, according to Standard EN 60529, i.e. for water. Even if the locking means which retains the pipe end in the hollow core space of the housing and secures it against being pulled out, is pre-assembled or connected with the housing, a practically unitary joining and connecting element results, which can be assembled without additional structural parts or handling steps in an extremely simple manner. The seals are also not lost during temporary disassembly, and the sealing effect is reliably ensured upon re-assembly.